Theorem xmulass 11989

Description: Associativity of the extended real multiplication operation. Surprisingly, there are no restrictions on the values, unlike xaddass 11951 which has to avoid the "undefined" combinations +∞ +_𝑒 -∞ and -∞ +_𝑒 +∞. The equivalent "undefined" expression here would be 0 ·_e +∞, but since this is defined to equal 0 any zeroes in the expression make the whole thing evaluate to zero (on both sides), thus establishing the identity in this case. (Contributed by Mario Carneiro, 20-Aug-2015.)

Assertion

Ref	Expression
xmulass	⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝐴 ·e 𝐵) ·e 𝐶) = (𝐴 ·e (𝐵 ·e 𝐶)))

Proof of Theorem xmulass

Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		oveq1 6556	. . . 4 ⊢ (𝑥 = 𝐴 → (𝑥 ·e 𝐵) = (𝐴 ·e 𝐵))
2	1	oveq1d 6564	. . 3 ⊢ (𝑥 = 𝐴 → ((𝑥 ·e 𝐵) ·e 𝐶) = ((𝐴 ·e 𝐵) ·e 𝐶))
3		oveq1 6556	. . 3 ⊢ (𝑥 = 𝐴 → (𝑥 ·e (𝐵 ·e 𝐶)) = (𝐴 ·e (𝐵 ·e 𝐶)))
4	2, 3	eqeq12d 2625	. 2 ⊢ (𝑥 = 𝐴 → (((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶)) ↔ ((𝐴 ·e 𝐵) ·e 𝐶) = (𝐴 ·e (𝐵 ·e 𝐶))))
5		oveq1 6556	. . . 4 ⊢ (𝑥 = -𝑒𝐴 → (𝑥 ·e 𝐵) = (-𝑒𝐴 ·e 𝐵))
6	5	oveq1d 6564	. . 3 ⊢ (𝑥 = -𝑒𝐴 → ((𝑥 ·e 𝐵) ·e 𝐶) = ((-𝑒𝐴 ·e 𝐵) ·e 𝐶))
7		oveq1 6556	. . 3 ⊢ (𝑥 = -𝑒𝐴 → (𝑥 ·e (𝐵 ·e 𝐶)) = (-𝑒𝐴 ·e (𝐵 ·e 𝐶)))
8	6, 7	eqeq12d 2625	. 2 ⊢ (𝑥 = -𝑒𝐴 → (((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶)) ↔ ((-𝑒𝐴 ·e 𝐵) ·e 𝐶) = (-𝑒𝐴 ·e (𝐵 ·e 𝐶))))
9		xmulcl 11975	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝐴 ·e 𝐵) ∈ ℝ*)
10		xmulcl 11975	. . 3 ⊢ (((𝐴 ·e 𝐵) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝐴 ·e 𝐵) ·e 𝐶) ∈ ℝ*)
11	9, 10	stoic3 1692	. 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝐴 ·e 𝐵) ·e 𝐶) ∈ ℝ*)
12		simp1 1054	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → 𝐴 ∈ ℝ*)
13		xmulcl 11975	. . . 4 ⊢ ((𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝐵 ·e 𝐶) ∈ ℝ*)
14	13	3adant1 1072	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝐵 ·e 𝐶) ∈ ℝ*)
15		xmulcl 11975	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ (𝐵 ·e 𝐶) ∈ ℝ*) → (𝐴 ·e (𝐵 ·e 𝐶)) ∈ ℝ*)
16	12, 14, 15	syl2anc 691	. 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝐴 ·e (𝐵 ·e 𝐶)) ∈ ℝ*)
17		oveq2 6557	. . . . 5 ⊢ (𝑦 = 𝐵 → (𝑥 ·e 𝑦) = (𝑥 ·e 𝐵))
18	17	oveq1d 6564	. . . 4 ⊢ (𝑦 = 𝐵 → ((𝑥 ·e 𝑦) ·e 𝐶) = ((𝑥 ·e 𝐵) ·e 𝐶))
19		oveq1 6556	. . . . 5 ⊢ (𝑦 = 𝐵 → (𝑦 ·e 𝐶) = (𝐵 ·e 𝐶))
20	19	oveq2d 6565	. . . 4 ⊢ (𝑦 = 𝐵 → (𝑥 ·e (𝑦 ·e 𝐶)) = (𝑥 ·e (𝐵 ·e 𝐶)))
21	18, 20	eqeq12d 2625	. . 3 ⊢ (𝑦 = 𝐵 → (((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶)) ↔ ((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶))))
22		oveq2 6557	. . . . 5 ⊢ (𝑦 = -𝑒𝐵 → (𝑥 ·e 𝑦) = (𝑥 ·e -𝑒𝐵))
23	22	oveq1d 6564	. . . 4 ⊢ (𝑦 = -𝑒𝐵 → ((𝑥 ·e 𝑦) ·e 𝐶) = ((𝑥 ·e -𝑒𝐵) ·e 𝐶))
24		oveq1 6556	. . . . 5 ⊢ (𝑦 = -𝑒𝐵 → (𝑦 ·e 𝐶) = (-𝑒𝐵 ·e 𝐶))
25	24	oveq2d 6565	. . . 4 ⊢ (𝑦 = -𝑒𝐵 → (𝑥 ·e (𝑦 ·e 𝐶)) = (𝑥 ·e (-𝑒𝐵 ·e 𝐶)))
26	23, 25	eqeq12d 2625	. . 3 ⊢ (𝑦 = -𝑒𝐵 → (((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶)) ↔ ((𝑥 ·e -𝑒𝐵) ·e 𝐶) = (𝑥 ·e (-𝑒𝐵 ·e 𝐶))))
27		simprl 790	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → 𝑥 ∈ ℝ*)
28		simpl2 1058	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → 𝐵 ∈ ℝ*)
29		xmulcl 11975	. . . . 5 ⊢ ((𝑥 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝑥 ·e 𝐵) ∈ ℝ*)
30	27, 28, 29	syl2anc 691	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e 𝐵) ∈ ℝ*)
31		simpl3 1059	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → 𝐶 ∈ ℝ*)
32		xmulcl 11975	. . . 4 ⊢ (((𝑥 ·e 𝐵) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝑥 ·e 𝐵) ·e 𝐶) ∈ ℝ*)
33	30, 31, 32	syl2anc 691	. . 3 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e 𝐵) ·e 𝐶) ∈ ℝ*)
34	14	adantr 480	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝐵 ·e 𝐶) ∈ ℝ*)
35		xmulcl 11975	. . . 4 ⊢ ((𝑥 ∈ ℝ* ∧ (𝐵 ·e 𝐶) ∈ ℝ*) → (𝑥 ·e (𝐵 ·e 𝐶)) ∈ ℝ*)
36	27, 34, 35	syl2anc 691	. . 3 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e (𝐵 ·e 𝐶)) ∈ ℝ*)
37		oveq2 6557	. . . . 5 ⊢ (𝑧 = 𝐶 → ((𝑥 ·e 𝑦) ·e 𝑧) = ((𝑥 ·e 𝑦) ·e 𝐶))
38		oveq2 6557	. . . . . 6 ⊢ (𝑧 = 𝐶 → (𝑦 ·e 𝑧) = (𝑦 ·e 𝐶))
39	38	oveq2d 6565	. . . . 5 ⊢ (𝑧 = 𝐶 → (𝑥 ·e (𝑦 ·e 𝑧)) = (𝑥 ·e (𝑦 ·e 𝐶)))
40	37, 39	eqeq12d 2625	. . . 4 ⊢ (𝑧 = 𝐶 → (((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)) ↔ ((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶))))
41		oveq2 6557	. . . . 5 ⊢ (𝑧 = -𝑒𝐶 → ((𝑥 ·e 𝑦) ·e 𝑧) = ((𝑥 ·e 𝑦) ·e -𝑒𝐶))
42		oveq2 6557	. . . . . 6 ⊢ (𝑧 = -𝑒𝐶 → (𝑦 ·e 𝑧) = (𝑦 ·e -𝑒𝐶))
43	42	oveq2d 6565	. . . . 5 ⊢ (𝑧 = -𝑒𝐶 → (𝑥 ·e (𝑦 ·e 𝑧)) = (𝑥 ·e (𝑦 ·e -𝑒𝐶)))
44	41, 43	eqeq12d 2625	. . . 4 ⊢ (𝑧 = -𝑒𝐶 → (((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)) ↔ ((𝑥 ·e 𝑦) ·e -𝑒𝐶) = (𝑥 ·e (𝑦 ·e -𝑒𝐶))))
45	27	adantr 480	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → 𝑥 ∈ ℝ*)
46		simprl 790	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → 𝑦 ∈ ℝ*)
47		xmulcl 11975	. . . . . 6 ⊢ ((𝑥 ∈ ℝ* ∧ 𝑦 ∈ ℝ*) → (𝑥 ·e 𝑦) ∈ ℝ*)
48	45, 46, 47	syl2anc 691	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e 𝑦) ∈ ℝ*)
49	31	adantr 480	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → 𝐶 ∈ ℝ*)
50		xmulcl 11975	. . . . 5 ⊢ (((𝑥 ·e 𝑦) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝑥 ·e 𝑦) ·e 𝐶) ∈ ℝ*)
51	48, 49, 50	syl2anc 691	. . . 4 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e 𝐶) ∈ ℝ*)
52		xmulcl 11975	. . . . . 6 ⊢ ((𝑦 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝑦 ·e 𝐶) ∈ ℝ*)
53	46, 49, 52	syl2anc 691	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑦 ·e 𝐶) ∈ ℝ*)
54		xmulcl 11975	. . . . 5 ⊢ ((𝑥 ∈ ℝ* ∧ (𝑦 ·e 𝐶) ∈ ℝ*) → (𝑥 ·e (𝑦 ·e 𝐶)) ∈ ℝ*)
55	45, 53, 54	syl2anc 691	. . . 4 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e (𝑦 ·e 𝐶)) ∈ ℝ*)
56		xmulasslem3 11988	. . . . . 6 ⊢ (((𝑥 ∈ ℝ* ∧ 0 < 𝑥) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦) ∧ (𝑧 ∈ ℝ* ∧ 0 < 𝑧)) → ((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)))
57	56	3expa 1257	. . . . 5 ⊢ ((((𝑥 ∈ ℝ* ∧ 0 < 𝑥) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) ∧ (𝑧 ∈ ℝ* ∧ 0 < 𝑧)) → ((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)))
58	57	adantlll 750	. . . 4 ⊢ (((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) ∧ (𝑧 ∈ ℝ* ∧ 0 < 𝑧)) → ((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)))
59		xmul01 11969	. . . . . . . 8 ⊢ ((𝑥 ·e 𝑦) ∈ ℝ* → ((𝑥 ·e 𝑦) ·e 0) = 0)
60	48, 59	syl 17	. . . . . . 7 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e 0) = 0)
61		xmul01 11969	. . . . . . . 8 ⊢ (𝑥 ∈ ℝ* → (𝑥 ·e 0) = 0)
62	45, 61	syl 17	. . . . . . 7 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e 0) = 0)
63	60, 62	eqtr4d 2647	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e 0) = (𝑥 ·e 0))
64		xmul01 11969	. . . . . . . 8 ⊢ (𝑦 ∈ ℝ* → (𝑦 ·e 0) = 0)
65	64	ad2antrl 760	. . . . . . 7 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑦 ·e 0) = 0)
66	65	oveq2d 6565	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e (𝑦 ·e 0)) = (𝑥 ·e 0))
67	63, 66	eqtr4d 2647	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e 0) = (𝑥 ·e (𝑦 ·e 0)))
68		oveq2 6557	. . . . . 6 ⊢ (𝑧 = 0 → ((𝑥 ·e 𝑦) ·e 𝑧) = ((𝑥 ·e 𝑦) ·e 0))
69		oveq2 6557	. . . . . . 7 ⊢ (𝑧 = 0 → (𝑦 ·e 𝑧) = (𝑦 ·e 0))
70	69	oveq2d 6565	. . . . . 6 ⊢ (𝑧 = 0 → (𝑥 ·e (𝑦 ·e 𝑧)) = (𝑥 ·e (𝑦 ·e 0)))
71	68, 70	eqeq12d 2625	. . . . 5 ⊢ (𝑧 = 0 → (((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧)) ↔ ((𝑥 ·e 𝑦) ·e 0) = (𝑥 ·e (𝑦 ·e 0))))
72	67, 71	syl5ibrcom 236	. . . 4 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑧 = 0 → ((𝑥 ·e 𝑦) ·e 𝑧) = (𝑥 ·e (𝑦 ·e 𝑧))))
73		xmulneg2 11972	. . . . 5 ⊢ (((𝑥 ·e 𝑦) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝑥 ·e 𝑦) ·e -𝑒𝐶) = -𝑒((𝑥 ·e 𝑦) ·e 𝐶))
74	48, 49, 73	syl2anc 691	. . . 4 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e -𝑒𝐶) = -𝑒((𝑥 ·e 𝑦) ·e 𝐶))
75		xmulneg2 11972	. . . . . . 7 ⊢ ((𝑦 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝑦 ·e -𝑒𝐶) = -𝑒(𝑦 ·e 𝐶))
76	46, 49, 75	syl2anc 691	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑦 ·e -𝑒𝐶) = -𝑒(𝑦 ·e 𝐶))
77	76	oveq2d 6565	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e (𝑦 ·e -𝑒𝐶)) = (𝑥 ·e -𝑒(𝑦 ·e 𝐶)))
78		xmulneg2 11972	. . . . . 6 ⊢ ((𝑥 ∈ ℝ* ∧ (𝑦 ·e 𝐶) ∈ ℝ*) → (𝑥 ·e -𝑒(𝑦 ·e 𝐶)) = -𝑒(𝑥 ·e (𝑦 ·e 𝐶)))
79	45, 53, 78	syl2anc 691	. . . . 5 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e -𝑒(𝑦 ·e 𝐶)) = -𝑒(𝑥 ·e (𝑦 ·e 𝐶)))
80	77, 79	eqtrd 2644	. . . 4 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → (𝑥 ·e (𝑦 ·e -𝑒𝐶)) = -𝑒(𝑥 ·e (𝑦 ·e 𝐶)))
81	40, 44, 51, 55, 49, 58, 72, 74, 80	xmulasslem 11987	. . 3 ⊢ ((((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) ∧ (𝑦 ∈ ℝ* ∧ 0 < 𝑦)) → ((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶)))
82		xmul02 11970	. . . . . . . 8 ⊢ (𝐶 ∈ ℝ* → (0 ·e 𝐶) = 0)
83	82	3ad2ant3 1077	. . . . . . 7 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (0 ·e 𝐶) = 0)
84	83	adantr 480	. . . . . 6 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (0 ·e 𝐶) = 0)
85	61	ad2antrl 760	. . . . . 6 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e 0) = 0)
86	84, 85	eqtr4d 2647	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (0 ·e 𝐶) = (𝑥 ·e 0))
87	85	oveq1d 6564	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e 0) ·e 𝐶) = (0 ·e 𝐶))
88	84	oveq2d 6565	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e (0 ·e 𝐶)) = (𝑥 ·e 0))
89	86, 87, 88	3eqtr4d 2654	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e 0) ·e 𝐶) = (𝑥 ·e (0 ·e 𝐶)))
90		oveq2 6557	. . . . . 6 ⊢ (𝑦 = 0 → (𝑥 ·e 𝑦) = (𝑥 ·e 0))
91	90	oveq1d 6564	. . . . 5 ⊢ (𝑦 = 0 → ((𝑥 ·e 𝑦) ·e 𝐶) = ((𝑥 ·e 0) ·e 𝐶))
92		oveq1 6556	. . . . . 6 ⊢ (𝑦 = 0 → (𝑦 ·e 𝐶) = (0 ·e 𝐶))
93	92	oveq2d 6565	. . . . 5 ⊢ (𝑦 = 0 → (𝑥 ·e (𝑦 ·e 𝐶)) = (𝑥 ·e (0 ·e 𝐶)))
94	91, 93	eqeq12d 2625	. . . 4 ⊢ (𝑦 = 0 → (((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶)) ↔ ((𝑥 ·e 0) ·e 𝐶) = (𝑥 ·e (0 ·e 𝐶))))
95	89, 94	syl5ibrcom 236	. . 3 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑦 = 0 → ((𝑥 ·e 𝑦) ·e 𝐶) = (𝑥 ·e (𝑦 ·e 𝐶))))
96		xmulneg2 11972	. . . . . 6 ⊢ ((𝑥 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝑥 ·e -𝑒𝐵) = -𝑒(𝑥 ·e 𝐵))
97	27, 28, 96	syl2anc 691	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e -𝑒𝐵) = -𝑒(𝑥 ·e 𝐵))
98	97	oveq1d 6564	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e -𝑒𝐵) ·e 𝐶) = (-𝑒(𝑥 ·e 𝐵) ·e 𝐶))
99		xmulneg1 11971	. . . . 5 ⊢ (((𝑥 ·e 𝐵) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒(𝑥 ·e 𝐵) ·e 𝐶) = -𝑒((𝑥 ·e 𝐵) ·e 𝐶))
100	30, 31, 99	syl2anc 691	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (-𝑒(𝑥 ·e 𝐵) ·e 𝐶) = -𝑒((𝑥 ·e 𝐵) ·e 𝐶))
101	98, 100	eqtrd 2644	. . 3 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e -𝑒𝐵) ·e 𝐶) = -𝑒((𝑥 ·e 𝐵) ·e 𝐶))
102		xmulneg1 11971	. . . . . 6 ⊢ ((𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒𝐵 ·e 𝐶) = -𝑒(𝐵 ·e 𝐶))
103	28, 31, 102	syl2anc 691	. . . . 5 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (-𝑒𝐵 ·e 𝐶) = -𝑒(𝐵 ·e 𝐶))
104	103	oveq2d 6565	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e (-𝑒𝐵 ·e 𝐶)) = (𝑥 ·e -𝑒(𝐵 ·e 𝐶)))
105		xmulneg2 11972	. . . . 5 ⊢ ((𝑥 ∈ ℝ* ∧ (𝐵 ·e 𝐶) ∈ ℝ*) → (𝑥 ·e -𝑒(𝐵 ·e 𝐶)) = -𝑒(𝑥 ·e (𝐵 ·e 𝐶)))
106	27, 34, 105	syl2anc 691	. . . 4 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e -𝑒(𝐵 ·e 𝐶)) = -𝑒(𝑥 ·e (𝐵 ·e 𝐶)))
107	104, 106	eqtrd 2644	. . 3 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → (𝑥 ·e (-𝑒𝐵 ·e 𝐶)) = -𝑒(𝑥 ·e (𝐵 ·e 𝐶)))
108	21, 26, 33, 36, 28, 81, 95, 101, 107	xmulasslem 11987	. 2 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) ∧ (𝑥 ∈ ℝ* ∧ 0 < 𝑥)) → ((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶)))
109		xmul02 11970	. . . . . 6 ⊢ (𝐵 ∈ ℝ* → (0 ·e 𝐵) = 0)
110	109	3ad2ant2 1076	. . . . 5 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (0 ·e 𝐵) = 0)
111	110	oveq1d 6564	. . . 4 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((0 ·e 𝐵) ·e 𝐶) = (0 ·e 𝐶))
112		xmul02 11970	. . . . 5 ⊢ ((𝐵 ·e 𝐶) ∈ ℝ* → (0 ·e (𝐵 ·e 𝐶)) = 0)
113	14, 112	syl 17	. . . 4 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (0 ·e (𝐵 ·e 𝐶)) = 0)
114	83, 111, 113	3eqtr4d 2654	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((0 ·e 𝐵) ·e 𝐶) = (0 ·e (𝐵 ·e 𝐶)))
115		oveq1 6556	. . . . 5 ⊢ (𝑥 = 0 → (𝑥 ·e 𝐵) = (0 ·e 𝐵))
116	115	oveq1d 6564	. . . 4 ⊢ (𝑥 = 0 → ((𝑥 ·e 𝐵) ·e 𝐶) = ((0 ·e 𝐵) ·e 𝐶))
117		oveq1 6556	. . . 4 ⊢ (𝑥 = 0 → (𝑥 ·e (𝐵 ·e 𝐶)) = (0 ·e (𝐵 ·e 𝐶)))
118	116, 117	eqeq12d 2625	. . 3 ⊢ (𝑥 = 0 → (((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶)) ↔ ((0 ·e 𝐵) ·e 𝐶) = (0 ·e (𝐵 ·e 𝐶))))
119	114, 118	syl5ibrcom 236	. 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (𝑥 = 0 → ((𝑥 ·e 𝐵) ·e 𝐶) = (𝑥 ·e (𝐵 ·e 𝐶))))
120		xmulneg1 11971	. . . . 5 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (-𝑒𝐴 ·e 𝐵) = -𝑒(𝐴 ·e 𝐵))
121	120	3adant3 1074	. . . 4 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒𝐴 ·e 𝐵) = -𝑒(𝐴 ·e 𝐵))
122	121	oveq1d 6564	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((-𝑒𝐴 ·e 𝐵) ·e 𝐶) = (-𝑒(𝐴 ·e 𝐵) ·e 𝐶))
123		xmulneg1 11971	. . . 4 ⊢ (((𝐴 ·e 𝐵) ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒(𝐴 ·e 𝐵) ·e 𝐶) = -𝑒((𝐴 ·e 𝐵) ·e 𝐶))
124	9, 123	stoic3 1692	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒(𝐴 ·e 𝐵) ·e 𝐶) = -𝑒((𝐴 ·e 𝐵) ·e 𝐶))
125	122, 124	eqtrd 2644	. 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((-𝑒𝐴 ·e 𝐵) ·e 𝐶) = -𝑒((𝐴 ·e 𝐵) ·e 𝐶))
126		xmulneg1 11971	. . 3 ⊢ ((𝐴 ∈ ℝ* ∧ (𝐵 ·e 𝐶) ∈ ℝ*) → (-𝑒𝐴 ·e (𝐵 ·e 𝐶)) = -𝑒(𝐴 ·e (𝐵 ·e 𝐶)))
127	12, 14, 126	syl2anc 691	. 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → (-𝑒𝐴 ·e (𝐵 ·e 𝐶)) = -𝑒(𝐴 ·e (𝐵 ·e 𝐶)))
128	4, 8, 11, 16, 12, 108, 119, 125, 127	xmulasslem 11987	1 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐶 ∈ ℝ*) → ((𝐴 ·e 𝐵) ·e 𝐶) = (𝐴 ·e (𝐵 ·e 𝐶)))

Syntax hints:   → wi 4   ∧ wa 383   ∧ w3a 1031   = wceq 1475   ∈ wcel 1977   class class class wbr 4583  (class class class)co 6549  0cc0 9815  ℝ^*cxr 9952   < clt 9953  -_𝑒cxne 11819   ·_e cxmu 11821

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847  ax-cnex 9871  ax-resscn 9872  ax-1cn 9873  ax-icn 9874  ax-addcl 9875  ax-addrcl 9876  ax-mulcl 9877  ax-mulrcl 9878  ax-mulcom 9879  ax-addass 9880  ax-mulass 9881  ax-distr 9882  ax-i2m1 9883  ax-1ne0 9884  ax-1rid 9885  ax-rnegex 9886  ax-rrecex 9887  ax-cnre 9888  ax-pre-lttri 9889  ax-pre-lttrn 9890  ax-pre-ltadd 9891  ax-pre-mulgt0 9892

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-nel 2783  df-ral 2901  df-rex 2902  df-reu 2903  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-iun 4457  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-po 4959  df-so 4960  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-riota 6511  df-ov 6552  df-oprab 6553  df-mpt2 6554  df-1st 7059  df-2nd 7060  df-er 7629  df-en 7842  df-dom 7843  df-sdom 7844  df-pnf 9955  df-mnf 9956  df-xr 9957  df-ltxr 9958  df-le 9959  df-sub 10147  df-neg 10148  df-xneg 11822  df-xmul 11824

This theorem is referenced by:  xlemul1  11992  xrsmcmn  19588  nmoi2  22344  xmulcand  28960  xreceu  28961  xdivrec  28966  xrge0slmod  29175